void init() {
neighbors_.resize(num_sites());
source_.resize(num_bonds());
target_.resize(num_bonds());
site_phase_.resize(num_sites());
bond_phase_.resize(num_bonds());
for (unsigned int s = 0; s < num_sites(); ++s) {
int x, y;
boost::tie(x, y) = index2xy(s);
site_phase_[s] = 2.0 * ((x + y) % 2) - 1.0;
for (unsigned int k = 0; k < 4; ++k) {
int d = 1- int(k & 2);
neighbors_[s][k] = ((k & 1) == 0) ? xy2index(x + d, y) : xy2index(x, y + d);
}
}
for (unsigned int b = 0; b < num_bonds(); ++b) {
unsigned int s = b / 2;
int x, y;
boost::tie(x, y) = index2xy(s);
unsigned int t;
if (b % 2 == 0) {
t = xy2index(x + 1, y); // target right
bond_phase_[b] = 2.0 * ((b / 2) % 2) - 1.0;
} else {
t = xy2index(x, y + 1); // target below
bond_phase_[b] = 2.0 * ((b / length_x_ / 2) % 2) - 1.0;
}
source_[b] = s;
target_[b] = t;
}
}
void init() {
source_.resize(num_bonds());
target_.resize(num_bonds());
site_phase_.resize(num_sites());
bond_phase_.resize(num_bonds());
for (unsigned int s = 0; s < num_sites(); ++s) {
int x, y;
boost::tie(x, y) = index2xy(s);
site_phase_[s] = 2 * ((x + y) % 2) - 1;
}
for (unsigned int b = 0; b < num_bonds(); ++b) {
unsigned int s = b / 2;
int x, y;
boost::tie(x, y) = index2xy(s);
unsigned int t;
if (b % 2 == 0) {
t = xy2index(x + 1, y); // target right
bond_phase_[b] = 2.0 * ((b / 2) % 2) - 1.0;
} else {
t = xy2index(x, y + 1); // target below
bond_phase_[b] = 2.0 * ((b / length_x_ / 2) % 2) - 1.0;
}
source_[b] = s;
target_[b] = t;
}
}
double hamiltonian::multiply(const double *v1, double *v0) const {
double prdct = 0;
for (int k = 0; k < num_bonds(); ++k) {
int isite1 = ipair_[k * 2];
int isite2 = ipair_[k * 2 + 1];
int is1 = 1 << isite1;
int is2 = 1 << isite2;
int is = is1 + is2;
double wght = 0.5 * bondwt_[k] * zrtio_[k];
for (int j = 0; j < dimension(); ++j) {
int ibit = config(j) & is;
double factor, offdg;
if (ibit == 0 || ibit == is) {
v0[j] -= wght * v1[j];
factor = 1;
offdg = 0;
} else {
v0[j] += wght * v1[j];
double temp = v1[config2index(config(j) ^ is)] * bondwt_[k];
v0[j] -= temp;
factor = -1;
offdg = -temp * v1[j];
}
prdct += - factor * wght * v1[j] * v1[j] + offdg;
}
}
return prdct;
}
